Learn Pasteurization, Only Three Minutes
author: HENTO time: Jan 17, 2018
The main principle of pasteurization:
Pasteurization is to heat the mixed feedstock to 68-70 ° C and rapidly cool to 4-5 ° C after 30 min. Because the general lethal point of the bacteria are temperature 68 ℃ and time is less 30min, so this method can kill pathogenic bacteria and the vast majority of non-pathogenic bacteria; rapid heat and cold changes can also contribute to the death of bacteria.
In a certain temperature range, the lower the temperature, the slower the bacteria to reproduce; the higher the temperature, the faster the propagation (the appropriate temperature for microbial growth generally 28 ℃ -37 ℃). But the temperature is too high, the bacteria will die. Different bacteria have different optimum growth temperature and heat resistance, cold tolerance. In fact, pasteurization make use of the pathogens not very heat-resistant characteristics, through the appropriate temperature and holding time treatment, kill all of them.
But after pasteurization, a small part of harmless or beneficial, heat-resistant bacteria or bacterial spores still retained, so pasteurized milk is stored at about 4 ℃ temperature, and can only be stored for 3 to 10 days.
